Chronic Constipation: What Manometry Tells Us About Gastro-Colonic Response and Pathophysiology

Findings from multiple methods of colonic manometry suggest an extrinsic neuropathy may be at play in severe functional constipation.

The latest research from a multinational team of clinician-scientists reveals that two common methods of high-resolution manometry testing — water-perfused and solid-state — offer equivalent information about the colon’s abnormal response to a meal among children with severe functional constipation. While the findings provide practical evidence supporting the use of either catheter type for such motility studies, the research also suggests something more revelatory about clinical management of functional constipation.

“Children who go years with suboptimal treatment for their constipation can end up with a colon that is dilated and dysfunctional, with poor motility,” says Desale Yacob, MD, medical director of the Motility Center at Nationwide Children’s Hospital and a coauthor of the study. “Most commonly, the distal colon can become unable to generate good contractions to help move stool out. The question is whether that is purely because it’s stretched out, or if it also eventually loses the ability to sense the feedback message from the gastro-colonic reflex.”

The team’s investigation of manometry findings for children with functional constipation spanned two main retrospective studies, the first analyzing water-perfused manometry findings in 18 patients and the second focusing on solid-state colonic manometry in 19 patients. The most recent results appeared in Neurogastroenterology & Motility in May. Both studies revealed an abnormal or absent response of the colon after a meal in the majority of patients, indicating that the type of catheter used for the evaluation does not impact results — a question the investigators had raised about their own findings after the initial water-perfused manometry study.

More importantly, perhaps, the overall findings of the manometry studies suggest neuropathic involvement in severe functional constipation. This is because the initial post-meal response in the colon is believed to be mediated by an extrinsic neural input. Since both children and adults with severe functional constipation show diminished response to a meal in the distal colon, it’s possible a neuropathy is actually at play.

“Our research efforts overall suggest that people may start with constipation that is functional in nature,” says Dr. Yacob. “But if you don’t make sure that the child can evacuate fully and regularly, then over time the colon can develop problems that are much more challenging to resolve.”

The researchers suspect that at some point, lack of effective treatment and regular bowel movements result in a change in the receipt of messages typically used to activate the colon’s contractions, since normal motility exists in the majority of the colon in many patients with severe constipation. Often, only the portions that store stool — the areas most affected by persistent constipation — are dysfunctional.

“We suspect that if you start with functional constipation due to behavioral and withholding problems, over time and without behavioral and medical intervention, it can lead to a much more involved problem that you can’t treat easily,” says Dr. Yacob. “Early, aggressive and effective treatment is crucial so that these problems don’t result in long-term, intractable dysfunction.”

The Motility Center at Nationwide Children’s performs in-depth history-gathering and motility studies with the goal of mapping the colon to identify and then treat the underlying issue causing constipation. The approach emphasizes early and aggressive treatment of severe constipation to avoid long-term progression and complications.

Dr. Yacob and colleagues at Nationwide Children’s have another high-resolution manometry study underway with fellow researchers from institutions in both the United States and the Netherlands to further quantify the colonic motor patterns in children with chronic intractable constipation.